C:\portable\Python35\python.exe %LOCALAPPDATA%\Android\Sdk\ndk-bundle\build\tools\make_standalone_toolchain.py --arch arm64 --api 24 --install-dir C:\toolchains\arm64-24
SET PATH=%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem
SET PATH=C:\toolchains\arm64-24\bin;%PATH%
CALL C:\cygwin\Cygwin.bat
cd /cygdrive/c/Qt/ffmpeg-3.4/
export TMPDIR=.
./configure --prefix=c:/Qt/3rdparty --arch=aarch64 --target-os=android --cross-prefix=aarch64-linux-android- --enable-{gpl,version3,static,asm,cross-compile} --disable-{shared,programs,doc,avdevice,avfilter,postproc,swscale,network,encoders,hwaccels,muxers,parsers,bsfs,devices,filters,bzlib,libopenjpeg,iconv,zlib}